'There was one right here about an hour ago!" says Torres del Paine park ranger Marta, delivering with gusto the news that we had just missed a puma. Kicking ourselves for having stopped for food en route, we keep our eyes peeled as we continue on to Lago Pehoe, a blue glacier lake in front of the spectacular granite "towers" of the Paine mountain range.
Our destination is Hosteria Pehoe, a simple hotel with an outstanding location on an island that can only be reached by footbridge. It was a 90-minute, 110km (70-mile) drive north from Punta Arenas airport, and, when we arrived, the evening sky looked as if it had been filled in with pink highlighter.
Most people come to Southern Patagonia for hiking, biking and kayaking, but mine is a strictly puma-related trip. I am on a "guaranteed puma" tour with SouthWild, a Latin American adventure travel company which offers a 100 per cent assurance that its guests will see at least one puma during a four-night stay in Torres del Paine National Park.
"You will see a puma most days if you're diligent about the hours," says Charlie Munn, who runs SouthWild. "It's not luck. Put in time at the right time and it's highly likely you will see them each day."
Native to the Americas, these slender, tan-coloured predators measure almost three-feet in height, making them the world's fourth-largest cat.
So confident is SouthWild of its puma promise, that it offers two nights and three days without charge (claimable within two years) should guests fail to see one during their initial stay. This makes puma spotting sound easy, as though all of the park's 150,000 annual visitors ought to see a large cat. But this is far from the case – partly because pumas are timid, nocturnal and solitary, but also because, for some inexplicable reason, no other hotel or tour operator offers puma tours.
And no, it's not as simple as just putting in the hours. SouthWild has also brought in the experts (namely park ranger and mountain-cat fanatic José Vargas Sandoval) to make sure its guarantee is fulfilled.
Rising before the sun, at 3.30am, I run across the footbridge where Charlie and José are waiting. José, who to my amusement is decked out in Puma-branded clothing, is alarmingly alert, given the hour, and laughs away as he tells me puma stories: "The other day a puma passed 10 metres from a German photographer. The guy didn't even see him, he was so busy looking at another puma in the distance!"
We pass Lago Mellizos (which means, oddly, "lake of the non-identical twins") and suddenly José switches into business mode. The windows are rolled down, his torch is fired up and he starts systematically spotlighting the dark hillsides. Maybe it's beginner's luck, or maybe José really does have a sixth sense, but within half an hour we find ourselves open-mouthed, gazing at two pumas on the roadside.
"They're young ones, less than a year... brothers," whispers José.
One is curious and approaches us, coming within two metres of the car. After an intense minute of looking right at us, he seems to decide we are uninteresting and playfully runs across to his more cautious brother. The pair then slinks off into the shadows.
José fills in time by returning to his big-cat tales, this time about a group of tourists who left their car door open and came back to find a puma in the passenger seat. Then 10 minutes later we catch sight of the brothers once more, their agile bodies gliding up and over a hill on the opposite side of the road.
As the sun rises, colour seeps into the park; and as the pumas go off to sleep, so their prey wakes up. Guanacos are everywhere. They are Patagonian llamas and are unique among their genus for having hair, not wool. They pose against mountain peaks, skip in single file across the rocky terrain, look after fluffy babies, and emit the occasional high-pitched alert if they see a puma.
Keeping a lookout is the job of male guanacos; they stand on high points overlooking the hilly terrain and belt out a donkey-like noise whenever a large cat comes into sight. Their signals come in handy for puma-spotting tourists.
The next morning we are up at dawn, and once more our efforts are rewarded as we spot a female cat on the hillside alongside us. We stop the car and take pictures like paparazzi as she crosses the road in front of us, walks down to the lake and vanishes from view.
By day three I've decided to have a "lie in", and José greets me with a "good afternoon" when I turn up at 4.50am. There's another car on the road this morning, a solo Brit on the hunt for pumas but with no guide and no luck thus far. We pass him by, turn a corner and suddenly hear the guanaco cry. We scan the hills and, sure enough, three pumas appear on a ridge before us.
After that we have plenty of non-puma sightings: we watch foxes chasing each other in the long grass, see a couple of skunks eating a hare, admire condors as they float past, and take pictures of Darwin's rheas (grey South American ostriches) running along the roadside, followed by lines of gawky chicks.
Nevertheless, and despite the fact that SouthWild has more than fulfilled its cat quota, I can't help but want to see just one more puma.
In the afternoon of my last day, I pull on three pairs of trousers and head out into the fearsome winds of the Torres del Paine. Finding a sheltered lookout among yellow gorse bushes, we settle in, and, by 8pm, Charlie is gently snoring. Then, as if it is saying goodbye, a puma arrives on a distant hilltop. She starts calling and two cubs appear against the lake. The sun sets behind them, blazing their silhouettes into the landscape.
Gabriel O'Rorke flew with LAN Airlines (0800 977 6100; lan.com), which flies from Heathrow via Madrid with prices starting from £850 return. Other options include Air France (0870 142 4343; airfrance.co.uk) from Heathrow via Paris, Iberia (0870 609 0500; iberia.com) via Madrid, and Air Canada (0871 220 1111; aircanada.com) via Toronto.
SouthWild (00 51 1422 9888; southwild. com) has packages from £1,895 per person for a five-day, four-night trip in Torres del Paine National Park. The price includes transfers to and from Punta Arenas, accommodation at Hosteria Pehoe (00 562 235 0252; pehoe.cl), transport for two puma searches per day, English-speaking naturalist guide, expert puma tracker, all meals, and the "puma guarantee".
Chile Tourist Board: chile.travel